This invention relates to polymerization catalysts and to a process of preparing the same. More particularly, this invention is directed to new solid catalysts which are suitable for the polymerization and the copolymerization of olefins and to a process of preparing the same.
U.S. Pat. No. 3,400,110 which was granted to Dassesse et al on Sept. 3, 1968 and which is incorporated herein by reference describes a process for the polymerization and the copolymerization of olefins in the presence of a catalyst obtained by activating with an organometallic compound, the reaction product of a compound of a transition metal with a solid compound comprising a hydroxychloride of a bivalent metal, which is preferably magnesium hydroxychloride, having the formula Mg(OH)Cl.
Though this is not yet established, it is believed that the reaction between the transition metal compound and the hydroxychloride of a bivalent metal, which produces the catalyst described in the above U.S. patent, is the result of a chemical bonding through the --OH groups of the hydroxychloride.
The catalytic complex comprises the following elements:
a bivalent metal M, preferably magnesium, PA1 chlorine, PA1 a transition metal M' bonded to the bivalent metal through oxygen, PA1 reactive groups X bonded to the transition metal. PA1 a bivalent metal M, preferably magnesium, calcium, manganese or cobalt, PA1 a halogen, PA1 oxygen, PA1 a transition metal chemically bonded to the support through oxygen, PA1 various substituents, which may be halogenated, bonded on the transition metal.
The catalytic polymerization processes described in the above U.S. patent, however, require that the bivalent metals be in the form of a hydroxychloride. These compounds which are not commercially available, cannot be obtained without difficulty and are costly to prepare.